1. Field of the Invention
The present invention relates to a micro lens array, a method of manufacturing the same, and a display device.
2. Description of Related Art
A micro lens array formed by arranging a plurality of micro lenses has been applied to liquid crystal panels, for example. Each lens of the micro lens array converges incident light upon each pixel to illuminate a display screen.
A micro lens array can illuminate a display screen, but a color display function has not been taken into consideration in conventional methods of manufacturing a micro lens array.
The present invention has been achieved to solve the above problem, and has as an objective thereof the provision of a micro lens array capable of displaying a color image as well as illuminating a screen, a method of manufacturing the same, and a display device.
(1) A method of manufacturing a micro lens array according to the present invention comprises:
a step of forming a color pattern layer including a plurality of pixels in a predetermined arrangement on a light transmitting substrate; and
a step of curving surfaces of the pixels in the color pattern layer corresponding to lens surfaces.
According to the present invention, pixels with curved surfaces corresponding to lens surfaces form a micro lens array. Since the pixels are formed by partitioning the color pattern layer, the pixels have the same color as the color pattern layer. Therefore, the micro lens array also has a function of a color filter.
(2) In this manufacturing method, the pixels in the color pattern layer may be formed with multiple colors;
in the formation of the color pattern layer, a step of forming a radiation sensitive layer having any one of the multiple colors on the substrate and then selectively removing part of the radiation sensitive layer to form part of the pixels may be repeated; and
in the step of curving the surfaces of the pixels, the pixels may be melted by heating to cause the surfaces of the pixels to be convexly curved by surface tension.
The pixels having the same one color are formed by selectively removing part of the radiation sensitive layer. Therefore, the color pattern layer can be formed by repeating the step of forming the radiation sensitive layer and selectively removing the radiation sensitive layer for a number of times corresponding to the number of colors of pixels.
(3) In this manufacturing method, the step of forming the color pattern layer may include a step of attaching a surface of a master mold on which a plurality of projections are formed to the substrate through a coloring material filling layer precursor, a step of removing the master mold from the coloring material filling layer precursor to form a coloring material filling layer having a plurality of recesses on the substrate, and a step filling each of the recesses with a coloring material having a predetermined color to form the pixels from the coloring material in the recesses; and
in the step of curving the surfaces of the pixels, the coloring material in the recesses may be melted by heating to cause the surface of the coloring material to be convexly curved by surface tension.
The coloring material filling layer having recesses can be formed by transferring the shape of the projections of the master mold to the coloring material filling layer precursor. The pixels are formed by filling the recesses with the coloring material, and the coloring material forming the pixels is melted by heating. The surfaces of the pixels are convexly curved by surface tension, whereby lens surfaces of a micro lens array can be easily formed.
(4) In this manufacturing method, the step of forming the color pattern layer may include a step of providing a partitioning member on the substrate to form a plurality of recesses capable of holding a liquid, and a step of filling each of the recesses with the coloring material having a predetermined color to form the pixels from the coloring material in the recesses; and
in the step of curving the surfaces of the pixels, the coloring material in the recesses may be melted by heating to cause the surface of the coloring material to be convexly curved by surface tension.
According to this method, the recesses are formed by providing the partitioning member on the substrate. The pixels are formed by filling the recesses with the coloring material, and the coloring material forming the pixels is melted by heating. The surfaces of the pixels are convexly curved by surface tension, whereby lens surfaces of a micro lens array can be easily formed.
(5) In this manufacturing method, the step of forming the color pattern layer may include a first step of providing a partitioning member on the substrate to form a plurality of recesses capable of holding a liquid, and a second step of filling each of the recesses with the coloring material having a predetermined color to form the pixels from the coloring material in the recesses, the partitioning member having the property of repelling the coloring material;
the step of curving the surfaces of the pixels may be carried out in the second step; and
the surface of the coloring material in the recesses may be convexly curved by being repelled by the partitioning member.
According to this method, the recesses are formed by providing the partitioning member on the substrate. The pixels are formed by filling the recesses with the coloring material. The partitioning member repels the coloring material. Therefore, only by filling the recesses with the coloring material, the surface of the coloring material can be convexly curved by being repelled by the partitioning member, whereby the lens surfaces of the micro lens array can be easily formed.
(6) In this manufacturing method, the partitioning member may be formed of a shading material.
The partitioning member is thus provided with a function of a black matrix.
(7) A method of manufacturing a micro lens array according to the present invention comprises:
a step of forming a light transmitting substrate in which a plurality of concavities having curved surfaces corresponding to lens surfaces are formed in a predetermined arrangement; and
a step of forming a color pattern layer in the concavities.
According to the present invention, the color pattern layer is formed in the concavities having curved surfaces corresponding to lens surfaces, and the lenses are formed in each concavity to form a micro lens array. Because the micro lens array has the color of the color pattern layer, the micro lens array also has a function of a color filter.
(8) In this manufacturing method, the step of forming the substrate may comprise a step of forming the concavities by etching a flat surface.
The shape of the concavities can be changed accurately as well as freely by changing the etching conditions.
(9) In this manufacturing method, the step of forming the substrate may comprise:
a step of attaching a surface of a master mold on which a plurality of convexities having a shape inverse to the concavities are formed to a reinforcing plate through a substrate precursor; and
a step of removing the master mold from the substrate precursor to form the substrate having the concavities on the reinforcing plate.
Since the shape of the convexities of the master mold is transferred to the substrate precursor to form the concavities, the concavities can be easily formed.
(10) This method of manufacturing a micro lens array may further comprise a step of removing the reinforcing plate from the substrate.
If the substrate itself has a sufficient strength, the reinforcing plate may be removed.
(11) In this manufacturing method, the step of forming the color pattern layer may be carried out by filling each of the concavities with a coloring material having a predetermined color.
(12) In this manufacturing method, the step of forming the color pattern layer may include a step of forming a coloring material receiving layer in a predetermined area including the concavities and a step of causing the coloring material having a predetermined color to be absorbed into the coloring material receiving layer in the concavities.
(13) In this manufacturing method, the coloring material receiving layer may be continuously formed in and over the concavities, and the coloring material may be absorbed into the coloring material receiving layer only within the concavities.
(14) In this manufacturing method, the coloring material receiving layer may be formed only in the concavities.
(15) A method of manufacturing a micro lens array according to the present invention comprises:
a step of forming a master mold including a plurality of concavities having curved surfaces corresponding to lens surfaces;
a step of forming a color pattern layer in the concavities; and
a step of removing the color pattern layer from the master mold.
According to the present invention, the color pattern layer is formed in the concavities having curved surfaces corresponding to lens surfaces, and the color pattern layer having a plurality of lenses corresponding to the concavities form a micro lens array. Because the micro lens array has the same color as the color pattern layer, the micro lens array also has a function of a color filter.
(16) This method of manufacturing a micro lens array may further comprise a step of attaching the color pattern layer to a reinforcing plate through a light transmitting layer precursor to form a light transmitting layer after the step of forming the color pattern layer and before the step removing the color pattern layer; and
the color pattern layer may be removed from the master mold together with the reinforcing plate and the light transmitting layer in the step of removing the color pattern layer.
If the color pattern layer cannot be removed independently from the master mold, the light transmitting layer may be formed in this manner.
(17) This method of manufacturing a micro lens array may further comprise a step of removing the reinforcing plate from the light transmitting layer.
If the light transmitting layer and the color pattern layer have a sufficient strength, the reinforcing plate may be removed. After the reinforcing plate is removed, the light transmitting layer functions as a protective layer for the color pattern layer.
(18) In this manufacturing method, the step of forming the color pattern layer may include a step of forming a coloring material receiving layer in a predetermined area including the concavities and a step of causing a coloring material having a predetermined color to be absorbed into the coloring material receiving layer in the concavities.
(19) In this manufacturing method, the coloring material receiving layer may be continuously formed in and over the concavities, and the coloring material may be absorbed into the coloring material receiving layer only within the concavities.
(20) In this manufacturing method, the coloring material receiving layer may be formed only in the concavities.
(21) In this manufacturing method, the coloring material may be provided by an ink jet method.
(22) A micro lens array according to the present invention is manufactured by the above-described method.
(23) A micro lens array according to the present invention comprises a plurality of pixels having surfaces as lens surfaces, and the pixels are arranged with multiple colors.
According to the present invention, the pixels having surfaces as lens surfaces form a micro lens array. Moreover, the pixels function as a color filter.
(24) A display device according to the present invention comprises the above described micro lens array and a light source which emits light toward the micro lens array.